This disclosure relates to biopsy systems and methods for talking a biopsy. More specifically, this disclosure relates to biopsy systems for removing multiple tissue samples.
In the diagnosis and treatment of breast cancer, it is often necessary to remove multiple tissue samples from a suspicious mass. The suspicious mass is typically discovered during a preliminary examination involving visual examination, palpitation, X-ray, MRI, ultrasound imaging or other detection means. When this preliminary examination reveals a suspicious mass, the mass must be evaluated by taking a biopsy in order to determine whether the mass is malignant or benign. Early diagnosis of breast cancer, as well as other forms of cancer, can prevent the spread of cancerous cells to other parts of the body and ultimately prevent fatal results.
A biopsy of the breast, for example, can be performed by either an open procedure or a percutaneous method. The open surgical biopsy procedure first requires localization of the lesion by insertion of a wire loop, while using a visualization technique, such as X-ray or ultrasound. Next, the patient is taken to a surgical room where a large incision is made in the breast, and the tissue surrounding the wire loop is removed. This procedure causes significant trauma to the breast tissue, often leaving disfiguring results and requiring considerable recovery time for the patient. This is often a deterrent to patients receiving the medical care they require. The open technique, as compared to the percutaneous method, presents increased risk of infection and bleeding at the sample site. Due to these disadvantages, percutaneous methods are often preferred.
Percutaneous biopsies have been performed using either fine needle aspiration or core biopsy in conjunction with real-time visualization techniques, such as ultrasound, mammography (X-ray), MRI, PET, CT, terahertz technologies, etc. Fine needle aspiration involves the removal of a small number of cells using an aspiration needle. A smear of the cells is then analyzed using cytology techniques. Although fine needle aspiration is less intrusive than an open procedure, only a small amount of cells are available for analysis. In addition, this method does not provide for a pathological assessment of the tissue, which can provide a more complete assessment of the stage of the cancer, if found. In contrast, in core biopsy a larger fragment of tissue can be removed without destroying the structure of the tissue. Consequently, core biopsy samples can be analyzed using a more comprehensive histology technique, which indicates the stage of the cancer. In the case of small lesions, the entire mass may be removed using the core biopsy method. For these reasons core biopsy is preferred, and there has been a trend towards the core biopsy method, so that a more detailed picture can be constructed by pathology of the disease's progress and type.
The first core biopsy devices were of the spring advanced, “Tru-Cut” style consisting of a hollow tube with a sharpened edge that was inserted into the breast to obtain a plug of tissue. This device presented several disadvantages. First, the device would sometimes fail to remove a sample, therefore, requiring additional insertions. This was generally due to tissue failing to prolapse into the sampling notch. Secondly, the device had to be inserted and withdrawn to obtain each sample, therefore, requiring several insertions in order to acquire sufficient tissue for pathology.
Vacuum assisted core biopsy devices were subsequently developed that required only a single insertion into the biopsy site to remove multiple tissue samples. An example of a vacuum assisted core biopsy device incorporates a tube within a tube design that includes an outer piercing needle having a sharpened end for piecing the tissue. The outer tube has an opening for receiving tissue. An inner tube is slidingly disposed within the outer tube, and serves to cut tissue that has prolapsed into the opening in the outer cannula. A vacuum is used to draw the tissue into the opening in the outer cannula.
Vacuum assisted core biopsy devices are available in handheld (for use with ultrasound) and stereotactic (for use with X-ray) versions. Stereotactic devices are mounted to a stereotactic unit that locates the lesion and positions the needle for insertion. In preparation for a biopsy using a stereotactic device, the patient lies face down on a table and the breast protrudes from an opening in the table. The breast is then compressed and immobilized by two mammography plates. The mammography plates create images that are communicated in real-time to the stereotactic unit. The stereotactic unit then signals the biopsy device and positions the device for insertion into the lesion by the operator.
In contrast, when using the handheld model, the breast is not immobilized. Rather the patient lies on her back and the doctor uses an ultrasound device to locate the lesion. The doctor must then simultaneously operate the handheld biopsy device and the ultrasound device.
While the vacuum assisted core biopsy device presented an advancement in the field of biopsy devices, several disadvantages remain with some of the currently marketed devices. For example, existing biopsy devices include multiple tubes to properly operate the device. Because the tubes are attached to various components of the biopsy device, all of these tubes (including tubes that do not come into contact with bodily fluids) are disposed of at the conclusion of the procedure, leading to waste and increased expense.
Another issue with current biopsy devices is insuring proper placement of a filter in a tissue collection chamber. Known biopsy devices, such as that disclosed in commonly owned U.S. patent application Ser. No. 11/132,034, the contents of which are incorporated herein in its entirety, include a filter body that is positioned with a tissue collection chamber. Vacuum is drawn through tissue collection chamber such that resected tissue cores are directed into the filter and retained therein for later examination, while blood and other fluids are pulled through the filter to exit the collection chamber. Once a biopsy cycle is completed, the filter may be removed from the tissue collection chamber, and the tissue cores may be retrieved for examination.
Because the filter is a separate removable piece from the collection chamber, during assembly of the biopsy device it may be inadvertently omitted from the collection chamber. Alternatively, the filter may be taken out of the collection chamber prior to use, but not replaced. However, if the filter is not properly placed within the tissue collection chamber, the resected tissue is not properly retained within the filter. Instead, resected tissue cores may pass through the tissue collection chamber and become lodged in the vacuum line, disabling the biopsy device and prohibiting examination of the cores. In some instances, the cores may also be flushed to a separate vacuum canister, along with other waste, in which case the physician may be able to recover the cores.
Another issue with prior art devices relates to different modes of operation of the device. For example, as described in commonly owned U.S. patent application Ser. No. 11/132,034, the contents of which are incorporated herein in its entirety, the biopsy device is operable in several different modes, including a “biopsy mode” and a “lavage mode.” In the biopsy mode, the device is taking tissue cores and delivering the cores to the tissue filter via the vacuum line. In the lavage mode, the biopsy device cylinder is vented, and then a saline flush is introduced to clear out biopsy cavity, as well as clearing out bodily fluids from the biopsy device. A console provides actuation mechanisms to switch between various modes. And if a physician attempts to tale tissue cores while the device is set in the lavage mode, the device will not operate, triggering malfunction alarms.
Further, for those biopsy devices that are used with Magnetic Resonance Imaging (MRI), the console must be placed outside of MRI suite where the device is being used. Thus, to switch between the modes, the physician is required to walk out of the suite thereby, leaving the patient's side, each time it is desired to switch between modes.
Another issue that may be experienced by users of the biopsy devices is not being able to cock the biopsy device (i.e., preparing the device for firing by retracting the outer cannula) for taking biopsy cores while the device is in the lavage mode. To prepare the device for taking tissue cores, the device requires pressure from the console to cock the device. The pressure is only available while in the biopsy mode. And if the device is cocked and fired in the lavage mode, the tissue aperture will be open, causing additional trauma to the patient.
Even if the biopsy device is in the cocked position, there still may be an issue with acquiring tissue. For example, if the device is in the cocked position, but the aperture is closed (the inner cutting cannula advanced forward), the aperture will not open during the biopsy cycle, and therefore tissue cores will not be acquired.
If the remote firing valve is not placed in the correct position, such as placing the remote valve between the cocked the fired positions so as only to partially cock the device, the device will not fully fire during the procedure and tissue may not be fully cut during the biopsy cycles.